Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5353893 | Elevator cab and/or counterweight compensation rope hitch assembly | Lu Sun | 1994-10-11 |
| 5080201 | Diversion of airflow around an elevator counterweight | Young S. Yoo, John K. Salmon | 1992-01-14 |